Nail and method for its manufacture



Sept. 21, 1943.

E, S. CLARKE NAILS AND METHOD FOR THEIR MANUFACTURE Filed July 20 1942 2 Sheets-Sheet l Sept. 21, 1943. E. s. CLARKE NAILS AND METHOD FOR THEIR MANUFACTURE 2 Sheets-Sheet 2 Filed July 20 1942 Patented Sept. 21, 1943 NAIL AND FEET-H0!) FOR ITS lvIANUFACTUBE 7 Eugene S. Clarke, Groveland, Mass, assigncrto United Shoe Machinery Corporation, Flemington, N. .L, a corporation of New Jersey Application July 1942, Serial No. 451,551

14 Claims. (01. s5-11) This invention relates to nails and their production, it being of special utility in connection with such fastenings employed for the attachment of heels to shoes. 1

In Letters Patent of the United States No. 2,200,385, Eich, May 14, 1940, is disclosed a nail utilized for'the above-mentioned purpose. This is of the collar-type formed from solid wire, with a shank at one side of the collar bifurcated and adapted to be inserted and clinched oppositely in the heel-seat of a shoe, while the shankat the opposite side of the collar may have'applied to it a hole formed in a heel to be attached. In this operation, the ends of' the divided shank are deflected outwardly after passing through the heelseat, to produce the clinch by contact with the heel-plate of the last upon which the shoe is mounted. To accomplish this w'iththebifurcation formed in the solid shank requires the -ap-' plication of'considerable force, and the last-plate tends quickly to 'be SO mutilated that it must be replaced. I Then, too, the amount of metal required for the solid-shank nail renders it expensive. My invention has as an object the provision of a nail, which may be clinched easily and effectively and which is relatively inexpensive.

In the attainment of this object, a feature of the invention consists of a nail formed of a strip of sheet-metal bent upon itself to furnish a body with its opposite sides connected and diverging from each other at one end, each side being convexed. outwardly to form a tubular shank. The connection between the sides of the body is at one end thereof. Such a nail, while glVing by its tubular shank ample trength to resist bending with a minimum amount of metal, provides by its diverging portions prongs which may be deflected and clinched by the applicationof a comparatively small force and with little effect upon the last-plate or other contactmember. To facilitate this clinching, the diverging'ends are preferably flattened. This also serves to penetrate the work more readily. 'As in the hail of the Eich easier its entrance into the work.

A further feature of the invention is concerned th convexed strip is bent;

with the manufacture of any improved nail. There is formed from sheet-metal a strip'having connected transversely convex portions, each provided Witha pointed end, said strip being bent preferably at a fiat central portio-n,'until the edges of the convex portions arein proximity to each other. This results in a nail having a bodyportion with atubular shank. By forminglthe opposite edgesof each of the convex portions first parallel to each other and then converging, upon bending'the strip theopposed parallel edges of the two'portions may be broughtinto substantial contact, while the corresponding converging edges of such portions will diverge from each'other-to give the desired bifurcation. Transverse 'enlargements are formed in the convex portionsand pressed at opposite sides to furnish a flattened collar, the pointed ends preferably being transversely flattened simultaneously therewith. In the accompanying drawings, illustrating my improved 'nail andimeans by which it maybe made, 1 Fig. 1 showsin perspective a blanked-out strip of sheet-metal having 'the 'desired peripheral contour; r h

Fig. 2 is a similar view-of the strip of Fig.1, which has been laterally-convexed;

Fig. 3, a side elevation of the strip of Fig. 2 bent into the preliminary 'form' of the nail-body; Fig. 4, a perspective view of the finished nail; Fig. 5, a separated perspective view of the blanking die and its punch; 1 r

Fig. 6, a like view of the lower'and upper conveXing dies; 7 l. r r Fig. 7, a vertical section of a fixture over which Fig. 8, a top plan view of clamping mechanism for the bent strip; l

Fig. 9, 'aperspective view of the pressure member bywhich the collar of the clamped nail is pressed and the points flattened; I l v I Fig. 10, a central vertical; section through the clamping mechanism and the co o'perating pressurememben Fig.'11, a side elevatio'nof apunch-press with the aid of whichthevarious naileforming operations maybe accomplished; and r Fig. 12, a verticaltransverse section illustrating a nail utilized .forlthe attachment ofa-heel to 351109. v w A lowerdie I0 (Fig. 5) includes-a plate I2, in which is anopening l'4 .having the contour of a blank A (Fig. 1), whichit is desired to cut. Upon per-plate I 8 in .which is'an opening 20 larger than the die-plate-opening l4. Between the spacers beneath the stripper-plate a channel 22 is formed, through which may be fed a ribbon of sheet-metal from which the blanks are to be cut. With the die l co-operates a punch 24, mounted upon a reciprocatory block 25 and so fitting the dieopening 14 that upon entrance thereto it will sever a blank from the sheet-metal in the channel 22. For this operation, the die 10 may be mounted upon the bed 28 of a punch-press P (Fig. 11), while the portion 24 is carried by the power-actuated plunger 30 of the press. The blank which the die and punch thus produce consists of a strip A, having at its center a neck 32 narrower than the adjacent portions 34, 34. The

opposite edges 35, 36 of each of these adjacent portions are parallel to each other, beyond which is a lateral curved projection 38 succeeded by terminal portions 39 having edges 40, 4G, first con-..

sion. The customary spring-actuated strippers 54 are associated with both dies to clear thework therefrom. They may be applied to the, punchpress P similarly to the blanking die and punch. The form of the, depression and projection is such that the neck 32 of the strip left flat. ut at each side the body-portions areuniformly con vexed transversely, except that, the areas at. the projections 38 are pressed more deeply, forming semi-circular beads or enlargements 55 extending outside the body-portions.

As the next step in the production. of the nail, a preliminary bend may be given to the: convex strip B with the aid of a fixture 56 (Fig. 7).. This is shown as an abutmentof angularf'orm, having a horizontal top wall 58 and a point 60, from which a lower wall 62 extends downwardly and rearwardly. Upon the upper wall, is agageprojection 64. The dimensions of. the fixture; are such that when the, operator lays one of the strip-portions 34, 39-; upon the wall 58 with the edges 36, down, the neck 32 is located over the point 60. The outer end, of the strip may thereupon be sent back so the opposite halveslie at an angle to each other. The fiatneck permits this to be done readily. With the:bend thus started symmetrically, the, opposite portionsof the strip may be forced; together morev closely, as appears at C in Fig. 3-.

To complete the formation of: the nail it is placed between a fixed member Glianda movable member 68 ofv the mechanism 10 of: Figs. 8, 9 and 10. The member 68 is shownasguidedfor horizontal movement upon rods 123.72.. and urged: normallyaway from its companion by expansion.- springs I4, 14. It may be forced into". clamping relation to the member 66 by. a. cam-lever, 16. With the clamping mechanism. mounted upon the bed. 28 of the punch-press P, the; bentstrip: C is placed with the connecting. neck; 32 downbetween registering recesses 18,. Him. the: members 6% and 6B. The undersides of the beads 55 rest upon horizontal. surfacestfl, 813,,which areat the bottom of enlarged recesses. 82;. 82. in. the members above the recesses 18.. llhere is applied to: the plunger 3-0. of. the press Pa pressure: member 84 This has a cylindricalmtermin'ali entering the recesses 82, with an end-surface 88 co-operating with the shoulders 80, 80. An axial bore 90 in the member 84 receives the upper portion of the nail-body. When the plunger of the press descends, the surface 88 bears upon the upper sides of the halves of the bead and compresses them, so "the upper and lower faces become parallel. Simultaneously with this action, the beveled end 92 of a projection 94 fixed in the bore 90 is forced between the opposed ends of the clamped strip, bending them back against the wall of the bore and flattening them laterally at 95, as is shown inFig. 10. When the plunger of the press is raised and the lever 16 retracted, the completed nail may be removed.

Referring to Fig. 4, the nail N has an elongated tubular body with its opposite sides joined at one extremity by the flat neck of the blank, which gives. a somewhat reduced point I00. The edges 36, 36 of each of the strip-portions 34 are now respectively parallel to those of the opposite portion, so there is formed a substantially cylindrical tubular shank I82. This extends to the compressed beads, which form together a compact annular flange or collar I04. The adjacent edges 46, 40 of the portions 39 first diverge gradually from the collar, and then more abruptly at the edges. d2, 42. There is thus furnished at this side of the collar the tubular bifurcated shank I86, 1% with the flattened; points 95, 95.

The nail N is shown in one of its applications in Fig. 12 of the drawings. Here, we have a tragment of the heel-seat-portion of a shoe S, into which has been driven the divided. portions I06, 186 of the nail N, which is but one of a set which WOllldbE employed; Because th points 95. are flattened, they penetrate the heel-seat material more readily than would the laterally convexed contour, and their considerable divergence starts promptly their separation from: each other upon insertion. Since these points are relatively thin, they bend readily, the clinch not only starting in the heel-seat material butalso progressing considerably therein, being completed upcn.- com.- paratively light engagement with the heel-plate l of the last L within the: shoe. This being the case, said plate sufierslittle mutilation. The less divergence of the portions IE6 along the edges 40 at the inner side of. the points make certain that clinch will be initiated in the right direction togive the maximum retaining effect: and that these portions will not be crumpled irregularly by a tendency to. bend inwardly. The tubular formoi the portions N36 is still maintained. The flat collar I04 is forced into the outsole s of the shoe, leavingthe shank I02 projecting. A heel H with holes, one of which is shown. at h, predrilled in the correct relation, is pressediuporr the na-il shank, the hole being. of somewhat smaller diameter than is the shank. The point tail iurnishes, a leader, causing ready reception otthe nail-shank by the heel-hole. The Wall or the hole grasps the shank, and the heel isheld firmly place by a fastening of ample strength. Having described my invention, what I claim as new. and, desire to secure by LettersPatent oi theUnited States is:

I. A nail. consisting of a. strip ofsheet-metal b'entuporr itself. to' furnish a body with. its opposite sides connected at one end: to fiurnish. a. reduced point andhavi-ng at. the other: end. spaced inaterialrpenetrating points, each side being-czarvexed outwardly to provide: atubular shank;

2. A nail consisting of astrip of sheet-metal bent upon itself. tc'furnishpa body. with itsiopposite sides connected at one end by a central portion narrower than the adjacent portions and diverging from each other at the other end to furnish spaced material-penetrating points, each side being convexed outwardly to provide a tubular shank,

3. A nail consisting of a strip of sheet-metal bent upon itself to furnish a body with its opposite sides connected at one end to furnish a reduced point and diverging from each other at the other end, each side being pointed and convexed outwardly to provide a tubular shank but with the diverging ends flattened at the points.

4. A nail consisting of a strip of sheet-metal bent upon itself to furnish a body with its opposite sides connected at one end and diverging from each other at the other end, there being a collar projecting from the body between the ends.

5. A nail consisting of a strip of sheet-metal bent upon itself to furnish a body with its opposite sides connected at one end and diverging from each other at the other end, there bein a collar projecting from the body between the ends and having substantially parallel opposite outer walls.

6. A nail consisting of a strip of sheet-metal bent upon itself to furnish a body with its opposite sides connected at one end and diverging from each other at the other end, there being a collar projecting from the body between the ends, the divergence between the sides starting in proximity to the collar.

7. A nail consisting of a strip of sheet-metal bent upon itself to furnish a body with its opposite sides connected at one end and diverging from each other at the other end, there being a collar projecting from the body between the ends, the divergence between the sides starting in proximity to the collar, it being first gradual and then more abrupt at the ends.

8; The method of manufacturing nails, which consists in forming from sheet-metal a strip with pointed ends and transversely convex at each side of its central portion, with said central portion flat and. of less width than the adjacent portions, and bending the strip at the flat portion until the edges of the convex portions are opposite each other.

9. The method of manufacturing nails, which consists in forming from sheet-metal, a strip transversely convex at each side of its central portion, said convex portions having opposite edges which are first parallel to each other and then converge, and bending the strip at the central portion until the opposed parallel edges of the two convex portions are in substantial contact and the converging edges of said two convex portions diverge from each other.

10. The method of manufacturing nails, which consists in forming from sheet-metal a strip transversely convex at each side of its central portion and with pointed ends, bending the strip at the central portion until the edges of the Convex portions are opposite each other, and flattending the pointed ends.

11. The method of manufacturing nails, which consists in forming from sheet-metal a strip transversely convex at each side of its central portion and with pointed ends, there being transverse enlargements formed in said convex portions, and beinding the strip at the central portion until the edges of the convex portions and their enlargements are opposite each other.

12. The method of manufacturing nails, Which consists in forming from sheet-metal a strip transversely convex at each side of its central portion and with pointed ends, there being transverse enlargements formed in said convex portions, bending the strip at the central portion until the edges of the convex portions and their enlargements are opposite each other, and pressing the opposite sides of the enlargements together to furnish a flattened collar surrounding the two convex portions.

13. The method of manufacturing nails, which consists in forming from sheet-metal a strip transversely convex at each side of its central portion and with pointed ends, there being transverse enlargements formed in said convex pcrtions, bending the strip at the central portion untilthe edges of the convex portions and their enlargements are opposite each other, pressing theopposite sides of the enlargements together to furnish a flattened collar surrounding the two convex portions, and flattening the pointed ends.

14. The method of manufacturing nails, which consists in forming from sheet-metal a strip transversely convex at each side ofits central portion and with pointed'ends, there being transverse enlargements formed in said convex portions, bending the strip at the central portion until the edges of the convex portions and their enlargements are opposite each other, clamping v the bent strip in this relation, pressing the oppo-' site sides of the clamped enlargements, and simultaneously therewith flattening thepointed ends.

EUGENE S. CLARKE. 

